Metallic receptacles



.F 1960 D. L. RICHTER 2,924,369

METALLIC RECEPTACLES Filed Aug. 17, 1955 INVENTOR DONALD L. RICHTERMETALLIC RECEPTACLES Donald L. Richter, akland, Calif., assiguor toKaiser Aluminum & Chemical Corporation, Oakland, Calif., a corporationof Delaware Application August 17, 19'55, Serial No. 529,058

7 Claims. (Cl. 229-35) This invention relates to receptacles formed oflight, thin sheet metal. More specifically, the invention relates to theproduction of and the resultant article which may be fabricated fromextremely thin sheet metal and particularly lightweight metals, such asaluminum foil. Specifically, the invention relates to the reinforcementof thin metal foils when the same are fabricated into containers.

'Thin metal foils, such as aluminum foil, have found wide-spread useinrecent years in the food container field. These foil containers may ormay not be disposable in nature. The use of such containers isparticularly prevalent throughout the baking industry wherein bakeryproducts may be cooked, stored and oftentimes quick frozen for use bythe householder at a subsequent date. Such containers generally take theform of a pie plate or similar article and the use specified is alsoextended to frozen foods, prepared foods, cakes, and the like whichrequire the provision of a cheaply fabricated, readily disposablebaking, storing or transporting receptacle. Because of the abuse andrough handling to which such containers are subjected, they must also berelatively strong and rigid.

- While the use heretofore of impregnated papers for such articleshasfound moderate success, the ready availability and advantages gainedfrom the use of moisture impermeable metal foils, such as aluminum foil,which may be of varying thickness, has resulted in a general acceptanceof said foil material for the purposes expressed. It will be appreciatedthat in the fabrication of such articles,'cost is a prime consideration.Accordingly, efforts have been, made toutilize extremely thin gauge'foilmaterial to reduce the cost of the fabricated receptacles'therebyenabling wider and more varied uses ofsuchr'eceptacles.'

Assa result of this tendency toward use of a thinner gauge metal foilmaterial, receptacles have been proportionately reduced instren'gth withthe result that the use thereof-for the purposes expressed has not atall times proven satisfactory;

Accordingly, theinvention relates to an arrangement for-reinforcingreceptacles made of light gauge sheet metal byprovidingsuitablyconfigured stamped or deep embossed geometric' patterns in thelower surface or bottom thereo'f'.wl1 il'e-at the same timeincorporating an improved rim'fstructure in the receptacle whereby theresultant -receptacle'will be sufficiently strong and capable of beingeasily fabricated of light, extremely thin gauge metal foil material. Itis an object of this invention to provide a 'novel receptacle which isstronger and more rigid, and which resists bending or deformation.

It isa principal object of this invention to provide a novel receptacleformed of light metal of extremely thin gauge'mat'eriall- I'Stillanother object of the invention is to provide a uniquely reinforcedreceptacle wherein the reinforcement is;ineor'porated in'the articlein-a novel fashion during formation of the article whereby even thoughmade of 0 Ice Patented Feb. 9, i9

Q extremely thin gauge metal foil such as aluminum foil the resultantcontainer will be exceptionally strong and rigid.

A further object of the invention is to produce a receptacle and areinforcement of such a receptacle to permit formation of the same ofextremely thin sheet material such that the resultant article will becomparative in strength to articles formed of material of considerablyheavier gauges or thickness.

These and various other objects of the invention will become moreapparent from an inspection of the drawings, wherein:

Figure 1 is a perspective view of an inverted, reinforced receptacleproduced in accordance with the instant invention;

Figure 2 is a sectional view taken through the receptacle shown inFigure 1 and discloses the lip portion as well as the sidewall andbottom portions of the receptacle, the hypothetical conical projectionof the lip and wall portions being indicated by dotted lines; and

Figure 3 is an enlarged partial sectional view through one of thereinforcing ribs of the receptacle when taken along the line 3-3 ofFigure 1, illustrating clearly the preferred form which such reinforcingelements should take.

In referring to the drawings and the following specification it is to beappreciated that the advantageous features of the instant invention maybe incorporated in a variety of receptacles and is not necessarilyconfined to the round receptacle specifically disclosed in Figure 1 ofthe drawing and described hereinafter. The advantages to be gained fromthe present invention, however, are attained with greatest particularityin an article of the type specifically referred to hereinafter.

As may be seen from an inspection of the drawings, the bottom surface ofthe receptacle disclosed is closed and is formed with suitably arrangedstamped or deep embossed portions which serve to reinforce thecomparatively large and generally unsupported extent of sheet materialin such a manner that bending and deflection of the bottom portion ofthe receptacle will be prevented.

Similarly, the wall and rim or flange portions of the structure are soarranged as to provide additional reinforcement of the entire structurewhereby not only the rim and wall portions, but the entire receptaclewill be considerably stronger than those'heretofore known in the art andwherein the reinforcement is of such a kind and nature as to permit theuse of extremely thin gauge materials, such as aluminum foil, in thefabrication of such receptacles.

Referring now in particular to Figure 1 it may be seen that thereceptacle comprises a flanged portion 1 arranged in circumscribingannular relation to the major body portion of the receptacle formedintegrally therewith. The major body portion of the receptacle comprisesa sloping wall 2. This wall portion 2 terminates in a disclike closedbottom 3. The sloping wall portion 2 and the integrally formed flangedportion 1 are so constructed that each comprises what may be considereda frustoconical surface. The projections of these surfaces as indicatedby the dotted lines in Figure 2, in effect, generate a pair ofoppositely facing conical surfaces which intersect generally at thepoints C and D. It has been discovered that the benefits to be gainedfrom the use of a peripheral flange on the wall portion 2 are enhancedto a considerable extent when the summation of the apex angles, A and Bas shown in Figure 1, of the cones generatedby the two surfaces 1 and 2approaches a sum of When the sumof the angles at the apices of theoppositely facing cones approaches this figure, it has been found thatthe wall portion 2 is reinforced to a considerably greater extent thanhas been obtained in the prior art receptacles wherein'such flanges havebeen generally disposed in a single plane extending across the top ofthe upper edge of the sloping wall portion.

In the case of the prior art devices referred to above, the angle of theflange with respect to the wall portion is such that any deflection ofthe wall tends to produce a bending of the flange in an upward directionsince the angle between the wall and the flange is considerably greaterthan 90 and a condition of stress resistant instability results fromsuch an angular relation. The flange then is generally not sufiicientlystable to perform its function of reinforcing the upper edge of thesloping wall portions.

In the disclosed structure, however, the conical flanged rim is sodisposed withrespect tothe wall} that any forces tending to distort thewall will be resisted by the flange which, by reason of the angularrelationship maintained, places a maximum amount of the flange materialin such a position that its stress resistant properties are effective tothe greatest possibleextent in resisting deflection and deformation ofthe wall 2.

Referring now in particular to Figure 2 of the drawing, it becomesapparent that the disc-like, closed bottom of the receptacle is subjectto considerable load imposed by any product confined within thereceptacle and that some means must be provided whereby the bottom maybe reinforced against bending or other destructive fiexure to which flatsheet elements are subject.

The reinforcing of the disc-like bottom may assume the form of stampedor deep embossed ribs or valleys wherein certain portions of thedisc-like bottom are interrupted relative to other portions and whereinthe uninterrupted portions are formed in effect into a series ofgeometric figures so arranged that the uninterrupted portions and thevalley portions will resist deflecting or bending loads imposed on thebottom structure. As is clearly evident from the drawing, thereinforcing pattern takes the form of a series of spaced trapezoids 5radiating outward from a hexagonal offset portion 4. The trapezoids areformed by providing the bottom with radially extending ribs or valleys 7which extend from the center of the pan outwardly toward the peripheralmarginal edge of the bottom structure. The valleys 7 are connectedtogether adjacent the center of the pan bottom by-a further series ofvalleys 9'so arranged as to generate the shorter edge of the trapezoids5 as well as to define and circumscribe the centrally disposed hexagonalportion 4 having its respective sides adjacent to the shorter sides oftrapezoids 5. The longer sideof the respective trapezoids 5 are disposedtoward the outer marginal edge of the bottom surface 3 of the pan. Thesesides are defined by depressing a portion of the metal such that adownwardly sloping bottom surface 6 is formed which extends from thelonger sides of each respective trapezoid outwardly and downwardlytoward the annular edge formed by the bottom 3 and its juncture with thesloping wall 2 when the receptacle is in article receiving position.

The bottom 3 of the pan or receptacle therefore may be considered to beprovided with a plurality of substantially symmetrical polygons disposedin concentric spaced relationship to each other such as inner hexagon 4,the axis of symmetry of which coincides with the center of the bottom3-, and an outer hexagon 4. Disposed between these polygons is a seriesof symmetrically arranged geometrical figures 5. These geometricalfigures 5 are partially defined or delineated by the generally radiallydisposed first series of diametrically interrupted ribs 7. Thedelineation of these geometrical figures 5 is completed by means of thesecond series of ribs 9 and, the lines of demarcation 10 that exitbetween the bottom surface portions 6 of the'receptacle and the mainbody portions of the geometrical figures 5.

In the preferred embodiment of the invention and reference is madespecifically to Figure 3, it may be seen that the ribs or valleys 7 and0 are comprised of generally V- .4 shaped walls formed integrally of thesame metal as the interrupted portions of the respective trapezoids andgeometrically figured center 4. The wall portions of the respectivegeometric figures define sloping, stress-resistant portions convergingtoward each other to produce V- shaped ribs or valleys which are notsusceptible to the same degree of flexure as areembossed rib-likemembers which include a fiat bottom interposed between spaced convergingwalls.

Considering now the entire structure, it may be seen that the radiallyextending ribs or valley portions may be spaced a maximum of-60 fromeach other such that no continuous or uninterrupted fold lines aboutwhich the bottom may be bent exists from any given point on theperipheral marginal edge to any diametrically opposed point on theperipheral marginal edge.

As shown in the drawing the trapezoids are disposed in such a mannerthat the valleys 7 and 9 are disposed 120 apart at their pointsofintersection, presenting no diametrically extending uninterruptedorcontinuous fold line about which the pan or receptacle bottom may flexor bend.- In the particular arrangement, the geometric figure at thecenter of the receptacle jbottom assumes the form of a hexagon.

Thus the bottom is reinforced insuch a manner that not only is bendingthereof by reason of its instability prevented, but also the nature ofthe embossed reinforcing does not present any fold lines" ordiametrically extending weakened areas about whichcollapse of ,thecontainer might occur as has been the case in most of the embossedreinforcing configurations contemplated in the prior art. Also,whereasthe prior art ,receptacles have been made of, for example,aluminum foil or sheet which is about 0.0033 to 0.0035 .inch inthickness, this invention enables the production of such receptacles ofthinner gauge metal sheet, especially aluminum foil.

In addition, considerable reinforcement is obtained by the use of thesloping edge 6 extending from the outermost portions of this disc-likebottom generally upwardly, or downwardly as viewed in Figure 2, to theupper edge of the sloping wall portions defining the longer side of therespective trapezoids 5, This position of the sloping wall orients themetal at anangle to the resultant force .vector of all of the forcesproduced by material carried Within the receptacle rather than disposingthe material at a right angle thereto. Since the foil or light metalfrom which the metal is fabricated has very little resistance to bendingunderordinary circumstances, the formation of the particular portions 6such as to generate a conical surface interrupted by the trapezoid andhexagon portions, in .turn interrupted by the ribs or valleys, willdispose a considerable amount of material at an angle such that theresistance of the metal to bending during handling is not dependentsolely on the gauge or thickness of the metal. Rather, the destructiveand re sistant components are resolved into a series of componentscomprised of both bending and compression vectors, the result of whichis to decrease the bending loads and increase the compressive loads thusplacing at least a part of the metal in a position of resistingcompression, at which it excels. Thus, the entire bottom of the panstructure is reinforced in such a manner as to enable unusually thinmaterial to perform a load supporting function and resistance to bendingor folding not possible with prior art devices even when embossed. Thus,thinner sheet material may be utilized than heretofore practical and theresults from the use of such thin material are to effect a considerablereduction in cost of the article, which reduction in cost is passed onto both the ultimate user as well as the commercial user. Thecompetitive position of light sheet foil in such uses is therebyenhanced costwise and its use becomes not only comparably favorable, butin many cases advantageous over materials heretofore used in the priorart.

To reiterate briefly, while an annularv or round receptacle has beendescribed, it must be appreciated that the particular principlesunderlying the advantages to be gained by the instant invention may bealso incorporated in receptacles having a configuration other thanannular or round as shown. In all cases it is to be remembered that thedisposition of the repsective ofi-set portions of the bottom must besuch that no continuous fold line is presented about which the bottommay flex or bend, and in particular, the offset connecting portions,namely, the ribbed or river elements, should be of the V-shaped designas clearly illustrated and described with reference to Figure 3 of thedrawing.

Having thus described the invention, what is claimed is as follows:

1. In a thin, light metal foil receptacle including a flangedfrusto-conical side wall and an integrally formed disc-like closedbottom, the improvement comprising inverted V-shaped integralreinforcement ribs formed in said receptacle bottom, said ribs being sodisposed and diametrically interrupted as to delineate a series ofsymmetrically arranged geometrical figures, said ribs beinginterconnected at their innermost terminal ends by a further series ofribs mutually interconnected to form and circumscribe a substantiallysymmetrical hexagon disposed with its axis of symmetry coinciding withthe center of the receptacle bottom, said bottom including further aperipheral edge portion inclined inwardly and upwardly from the plane ofthe bottom and merging with said series of geometrically delineatedfigures, said reinforcement ribs and said inclined edge portion servingto resist bending and folding of said receptacle bottom.

2. A thin, light metal receptacle as defined in claim 1, wherein saidflange on said frusto-conical side wall is disposed at an angle suchthat it comprises a further oppositely inclined frusto-conical surfaceand wherein the sum of the apex angles of the oppositely facing cones,upon generation, closely approximates 180.

3. The combination defined in claim 1, wherein the metal making up saidreceptacle is thin gauge aluminum foil.

4. In a thin metallic foil receptacle including a flange, a sloping sidewall and an integrally formed closed bottom, the improvement comprisingintegral reinforcing ribs formed in said receptacle bottom, said ribsbeing so disposed and diametrically interrupted as to delineate a seriesof symmetrically arranged geometrical figures, said ribs beinginterconnected at their innermost terminal ends by a further series ofribs mutually interconnected to form and circumscribe a substantiallysymmetrical polygon disposed with its axis of symmetry coinciding withthe center of the receptacle bottom, said bottom further including aperipheral edge portion inclined inwardly and upwardly from the plane ofthe bottom and merging with said series of geometrically delineatedfigures, said reinforcing ribs and said inclined edge portion serving toresist bending and folding of said receptacle bottom.

5. A thin metallic foil receptacle as defined in claim 4 wherein saidflange and side wallcomprise converging frusto-conical surfaces disposedat such an angle to each other whereby the sum of the apex angles of the0pposite facing cones formed upon generation of said surfaces closelyapproximates 6. A thin metallic foil receptable comprising a slopingside wall provided with a flange and an integrally formed closed bottom,said closed bottom having a first series of reinforcing ribs so disposedand diametrically interrupted as to partially delineate a plurality ofsymmetrically arranged geometrical figures, said ribs beinginterconnected at their innermost terminal ends by a second series ofribs which circumscribe and form a substantially symmetrical polygondisposed with its axis of symmetry coinciding with the center of thereceptacle bottom and said first-mentioned series of ribs also beinginterconnected at their outermost terminal ends by demarcation lineswhich circumscribe another symmetrical polygon the shape of whichsubstantially coincides with that of the first-mentioned polygon andsaid second-mentioned series of ribs and said lines of demarcationcompleting the delineation of said geometrical figures.

7. A foil receptacle as defined in claim 6 wherein said side wallcomprises a frusto-conical surface and said flange on the sidewall isdisposed at an angle thereto such that it comprises a further oppositelyinclined frustoconical surface and wherein the sum of the apex angles ofthe oppositely facing cones generated by said surfaces closelyapproximates 180.

References Cited in the file of this patent UNITED STATES PATENTS476,340 Wagandt June 7, 1892 1,689,018 Froidevaux Oct. 23, 19281,865,742 Chapman July 5, 1932 1,866,035 Hart et al. July 5, 19322,036,572 Frost Apr. 7, 1936 2,041,537 Frost May 19, 1936 2,080,125Frost May 11, 1937 2,170,040 Stuart Aug. 22, 1939 2,174,425 SchlumbohmSept. 26, 1939 2,673,003 Stewart Mar. 23, 1954 2,703,185 Cook Mar. 1,1955 2,775,383 Kollman et al. Dec. 25, 1956 FOREIGN PATENTS 8,163 GreatBritain 1901

